Fluid cooled reamer with land channel



Nov. 9, 1965 R. w. ANDREASSON FLUID COOLED REAMER WITH LAND CHANNEL 2Sheets-Sheet 1 Original Filed Jan. 8, 1963 Nov. 9, 1965 R. w. ANDREASSONFLUID COOLED REAMER WITH LAND CHANNEL 2 Sheets-Sheet 2 Original FiledJan. 8, 1963 INVENTOR.

N s w. H a w A M 5 M r 1 r w A A r United States Patent 3,216,107 FLUIDCOGLED REAMER WITH LAND CHANNEL Rudolf W. Andreasson, R0. Box 174,Birmingham Mich. Continuation of abandoned application Ser. No. 250,076,Jan. 8, 1963. This application May 27, 1965, Ser. No.

3 Claims. (Cl. 29-567) This is a continuation of application Serial No.250,076, January 8, 1963, and now abandoned.

This invention relates to a reamer and more particularly to the type ofreamer which is used for reaming of blind holes although it may also beadapted to reamers which are used for open ended holes. Reference ismade to my Patent No. 3,055,239, issued September 25, 1962, and to myco-pending application Serial No. 206,972, filed July 2, 1962, nowPatent No. 3,169,417, issued February 16, 1965, wherein there aredisclosures of reamers of the general type under consideration.

It has been common in the drill and reamer art to provide coolantthrough a center passage in the shank. In some cases it has beendischarged into the flute at a distance from the tip to cause a flushingdown of the chips as well as lubrication and cooling. In other cases, ina blind hole, the coolant is discharged at the end of the tool so itwill flow back along side flutes to wash chips up along the flutes tothe entrance of the hole.

Whether a tool has been a single flute or multiple flute tool, it hasalso been common practice to provide clearance on the lands between theflutes. This clearance is sometimes created by brazing wear strips onthe lands at the leading and trailing edges of the land. More often theclearance is ground into the land leaving a contact strip at the leadingand trailing edge of the land. Due to deflection from grinding wheelpressure, the trailing surface of the land is subject to more pressureand is of consequent greater elfective diameter than the leading surfacewhich gets the initial contact of the wheel before wheel pressureperceptively deflects the tool. With any carelessness at all in thegrinding, the discrepancy between the contact surfaces of the land maybe as much as .001" or more. This can cause a burning or galling orrubbing of the hole wall since the cutting or sizing edge is smallerthan the trailing edge. On the other hand, with proper coolant andlubrication, this discrepancy can create a beneficial effect in that thelarger trailing edge can coin, burnish, or bearingize the surface toimprove the finish materially.

Accordingly, it is an object of the present invention to provide a holeforming or enlarging tool wherein an insert can be associated with atool shank in a way to provide adequate lubrication of the cutting tip,where this is required, and also adequate cooling and lubrication of thebearing surfaces of the tool to provide improved wall surface resultsand avoid any danger of rubbing or burning.

It is a further object to provide a combination tool shank and bitinsert wherein a positive drive is provided between the two which alsoadapts to the furnishing of adequate coolant both to the cutting tip andto the wall of the hole. Another feature of the construction is thecontrolled flow which eliminates waste of the coolant and greatlyreduces the need for guide bushings.

It is also an object to provide a reamer which is relatively inexpensiveto manufacture and one in which a hard cutting insert can be readilyapplied to an inexpensive reamer shank to provide an economical tool.

Other objects and features of the invention relating to details ofconstruction and operation will be apparent in the following descriptionand claims.

3,216,107 Patented Nov. 9, 1965 ice Drawings accompany the disclosureand the various views thereof may be briefly described as:

FIGURE 1, an elevation of the reamer partially in section showing onemodification of the device.

FIGURE 2, an end view of the reamer of FIGURE 1.

FIGURE 3, a side elevation of the reamer insert.

FIGURE 4, a top view of FIGURE 3 at line 4.

FIGURE 5, a side elevation of the shank end with the reamer separated.

FIGURE 6, a sectional view on line 66 of FIGURE 5.

FIGURE 7, a side elevation of a modified structure showing a two-fluteddevice.

FIGURE 8, an end view on line 8-8 of FIGURE 7.

FIGURE 9, a view of the shank end with the reamer insert separatedtherefrom.

FIGURE 10, a sectional view of the shank on line 1010 of FIGURE 9.

FIGURE 11, an enlarged elevation of the reamer insert of FIGURE 7.

FIGURE 12, a side view of the reamer insert on line 12-12 of FIGURE 11.

FIGURE 13, a top end view of the reamer insert taken on line 13 ofFIGURE 11.

Referring to the drawings:

In FIGURE 1, a reamer insert 18 is shown with a shank 20 which is in theform of a steel tube having a central opening 22, the opening at the endof the shank having a slight enlargement 24 leading to a tapered recess26 as shown in FIGURE 5. The end of the shank to which the reamer insertis joined has an interdigital formation formed by alternate slots 28 and29 and alternate skirts 30 and 31. It will be noted (FIGURE 6) that theslots 28 have one angled side for purposes to be later noted. An endview of the insert (FIGURE 3) to be applied to shank 20 illustrates theshape to include a series of flutes 32 separated by land portions whichfor convenience will be referred to as 3436, these portions beingseparated by a channel 38. In the embodiment shown, each flute 32terminates in a cutting and wear land 40 which can be a strip of carbidebrazed into a recess 42 at the edge of lands 36. A wear strip 44 is alsobrazed to a small axial groove on the surface of the lands 34.

As shown in FIGURES 3 and 4, the flutes 32 connect at the top to anangled channel 46 While the channels 38 are extended angularly towardthe upper tip of the reamer in short channels 48. When the end of theshank 20 is joined with the shank end of the insert 18, the variousskirt-like digital projections will interfit with the respective flutes32 and channels 38 of the insert to provide positive engagement and theparts are joined together by a suitable adhesion method such as brazing.In this mating operation, it will be seen that the skirts 30 will enterthe wider flute formations 32 while the skirts 31 will enter thenarrower channel formations, the channel formations being suitablywidened at the shank end to provide recesses 50 to receive the edges ofthese skirts. Thus, the hard insert which may be carbide or high speedsteel is mechanically engaged with the shank. In addition, each flute 32is connected to the center opening 22 of the shank 20 through theopenings 46 and each channel in land 3636 is connected also to thecenter opening through the short channels 48.

The reamer inserts, of course, are ground to size and finished by theuse of a grinding wheel. It has been detected that in this grindingoperation, there is a certain deflection phenomenon which takes placeparticularly in the smaller sizes so that in the initial contact of thegrindwheel with the flute portion being ground, the dimension will beless than the trailing portion of the flute which is ground because, asthe grinding wheel progresses circumferentially on the land, thedeflection becomes greater and thus the actual material which is groundaway is less. Thus, a situation develops where the actual cutting edgeof a member 40 may be of smaller diameter than the trailing edge of thatsame cutting piece.

For this reason, in difficult work where finish is extremely important,the present design is ideal since not only can the cutting edge beflooded with coolant and lubricant through the channels 46 and theflutes 32, but also the trailing edges by which the reamer is supportedin the hole can be equally well lubricated and protected by a force-flowthrough channels 48 and 38. It will be seen that the angled channels 48are no longer than the channels 46. The reason for this is that it isdesirable that the fluid flowing through the channels 46 will bedeflected by the skirts 30 to dissipate the outward component of thecoolant and flow axially straight down the flute 32, thus insuring thatthe fluid reaches the end of the reamer in suflicient supply tolubricate the working end as well as the edges. On the other hand, withrespect to channel 48 and channel 38, the lubricant is particularlyadapted for the protection of the walls of the hole relative to thelands of the reamer.

Thus, the longer channel 48 is still protected by a skirt portion 31 ofthe shank and the fluid will flow primarily down the channel to the endof the tip. Since the channel 48 is longer than channel 46 and since thechannel 38 is shallower than the flute 32, the fluid carried therein isnearer the wall surfaces of the hole and thus, together with thecentrifugal force of operation, will force the lubricant between thelands and the walls to perform its function of cooling and lubricating.Thus, a superior job is performed by reason of the tool design. The unitshown in FIGURES l to 4 is especially adapted for open-end holes.

In FIGURES 7 to 13, an embodiment of a reamer construction is shownwhich is particularly adapted for use with blind holes where it isessential that the chips be flushed out by the coolant as the reamerprogresses. A reamer shank 60 having a central passage 62 is joined withan insert 64. The reamer shank has a relatively long flute 66 formedtherein to permit escape of chips. This flute can extend as far up alongthe shank as is necessary to allow the chips to flow out of the holebeing reamed. The center hole of the shank 60 is enlarged slightly at 68and tapered at 70 to the opening of the shank, this shank being providedwith two projecting skirt portions 72 on opposite sides of the shank.

The insert is provided with two relatively wide flutes 74 separated bysplit land portions 76-78 lying on either side of axial surface channels80, these channels being angled inwardly at the top portion of theinsert in short channels 82. These short channels 82 are widened toprovide side recesses 84 which receive, in assembly, the edges of theskirts 72. Each flute 74 of the insert can connect at the shank end witha similar flute 66 in the shank. When the parts are brazed together, itwill be seen, of course, that the skirts 72 are mechanically engagedwith the end of the insert and the channels 82 connect to the centralpassage 62 of the shank. The walls of the shank blend in with thetapered top end of the insert 64 so that the respective flutes of theinsert and the shank are joined with no connection to the interiorpassage 62 of the shank.

In FIGURE 8, the lands 7678, interrupted by the grooves 80, are shownwith clearance ground into the surfaces, the leading edge surface 90 andthe trailing edge surface 92 being the wall contacting surfaces in theoperation. It is these surfaces which may vary in diameter, as abovedescribed, and it is these surfaces which receive the direct lubricationfrom channels 80 which in turn furnish abundant quantity of coolant tothe tip of the tool and assist in the flushing out of the chips throughflute 66.

Thus, all the coolant will flow from the shank through the channels82-80 and reach the end of the reamer in access to the outside of thetool.

such a way that the end will be flooded with coolant and carry the chipsup through the larger flutes. In addition, coolant coming down throughthese channels will cool and lubricate the guiding lands 94 and 96 ofthe reamer and, as pointed out above, the trailing land 96, which, as aresult of grinding, is somewhat larger than the leading land 94, is welllubricated with this arrangement so that any burning or galling of thewalls of the hole is prevented. However, the burnishing or bearingizereffect is accomplished by these trailing lands which have contact withthe walls of the hole and which, when properly lubricated, may improve afinish from a 20-micro finish to a 10-micro finish.

It will be noted that in both the above described embodiments, lookingat an end view of the tip toward the shank, it is possible to see adirect straight line relationship through the channels and flutes intothe passages within the skirt portions of the shank. In FIGURE 2, forexample, the flutes 32 open directly into the passages 46 as viewed fromthe end, and the channels 38 open directly into the passages 48.Similarly, in FIGURE 8, the flutes 80 open directly into the passages82.

It will be seen from the above description that the design of the toolis such that it is adaptable not only to extremely large tools but alsoto extremely small tools. Many previous designs have required a drillingof the insert in order to provide the coolant holes which give Thepresent device has no holes drilled but simply requires the outer flutesto be carried into the surface of the tapered end and thus connect up tothe axial passage of the shank. Thus, extremely small tools can beprovided with ample coolant passages.

Another advantage of the device lies in the fact that a relatively largeare-a of metal-to-metal contact is provided in the joint between theshank end and the bit with the interlocking skirts being brazed to thewalls of the slots formed for them and the land portions of the taperedinsert being in contact with the tapered recess of the shank. The toolhas, therefore, the advantage of an interlock drive as well as a largearea of brazing surface.

Another advantage of the above described structure lies in the fact thatit may be used for what are called stepped-tools, that is, tools whichhave, for example, three different diameters increasing from the tip upto the shank. With the flute extending from the coolant passage rightdown to the tip and with the direction of the coolant being such that itclings closely to the flute, it is possible to use much longer sectionsfor each stepped portion without concern as to whether the coolant willhit the cutting edge and thus the tool life is much longer.

With the disclosed structure, the coolant moves straight down the flutesand even in a horizontal tool the coolant will be shooting rightstraight off the end of the tool as it projects toward the hole to bedrilled or reamed. Thus, advantage can be taken of the centrifugal forcewhich will move the fluid out against the walls of the hole beingenlarged or finished; and because of the construction, there will be anassurance that there will be ample cooling and lubricating liquidthrough the length of the tip available for cooling the cutting edges aswell as lubricating the walls of the hole. In addition, in the structureshown in FIGURES 1 to 6, for example, it will be noted that there iscoolant flowing on each side of the cutting lands. Thus, even a highspeed operation can be accomplished without overheating of the cuttingportions of the tool.

Another object and advantage of the design above described is found inthe above features which include the coolant flowing down the flute andclinging to the tool. This not only reduces the need for guide bushingswhich are in some cases provided primarily to hold in the coolant, butit also greatly increases the advantage of the device when in stepdrilling or reaming the small portion of the tip must Work before theother portions reach contact with the surfaces which they are :tooperate on. With the fluid moving right down to the tip, it is availableas soon as any portion of the tip starts its work. Thus, a guide bushingwhich is large enough for the biggest portion of the tip cannot aid thesmall portion of the tip and this is no longer required with the presentconstruction.

Similarly, if a tool is being used on an intricate casting, for example,where there are interrupted cuts, the use of coolant holes which directthe coolant radially outward or aslant to the tool is practicallyuseless in furnishing fluid to the small tip because it flies outthrough the openings in the casting and never reaches the small portionof the tip. Thus, there are numerous features and advantages which flowfrom the construction which not only provides a locking drive but also agreater bonding area and a greatly improved flow characteristic forcoolant.

It will be apparent, of course, that the tip can be made of solidtungsten carbide or a similar hard material and also from tool steel orhigh speed steel if desired. The present day equipment which permitsvery rapid brazing makes the reamer practically a replaceable part sothat should one tip be ground away by reason of frequent sharpenings ordestroyed by accident, the same shank can be used again with anothertip. The direct engagement between the tip and the shank provides apositive drive relationship; and in severe conditions when the brazedjoint might become softened by abnormal heat due to a momentary cut-offof the coolant, the parts will continue to drive and there can be nodestruction or slipping.

In the appended claims, I have attempted to delineate the novelty of mydevice over known prior art for the purpose of defining the protectedarea as well as notifying the public relative to the unprotected area.However, I do intend by this claiming to cover any colorable variations,reversal of parts, or equivalents of the device which are within thescope and spirit of this disclosure and not anticipated by the priorart.

What is claimed as new is as follows:

1. In a hole enlarging and finishing tool such as a reamer of the typehaving a shank with an axial coolant passage and a bit bonded to saidshank, that improvement which comprises:

(a) an elongate bit having a shank end and a cutting end and arelatively large flute with a cutting edge along one axial sidecontinuing in a radial edge extending inwardly from the periphery of thebit at the cutting end, and a land extending circumferentially from saidflute forming a bearing surface for said tool, said land having leadingand trailing axial surfaces extending along leading and trailing edgesthereof and being relieved slightly between said surfaces, the leadingsurface being slightly smaller in diameter than the trailing surface ofsaid land, and a relatively shallow axial surface flute formed on saidland from one end to the other, between said leading and trailingsurfaces, and

(b) a shank having :a coolant passage terminating in a recess to receivea portion of one end of the bit opposite the cutting end, the walls ofsaid shank adjacent said recess having axial projections to insert intoand overlie said flutes adjacent the surface of cal said bit to create amechanical interlock for a torque drive between said shank and said bitand to direct coolant down said flutes to the cutting end of said bit.

2. In a hole enlarging and finishing tool such as a reamer of the typehaving a shank with an axial coolant passage and a bit bonded to saidshank, that improvement which comprises:

(a) an elongate bit having a shank end and a cutting end and arelatively large flute with a cutting edge along one axial sidecontinuing in a radial edge extending inwardly from the periphery of thebit at the cutting end, and a land extending circumferentially from saidflute forming a bearing surface for said tool, said land having leadingand trailing axial surfaces extending along leading and trailing edgesthereof and being relieved slightly between said surfaces, the leadingsurface being slightly smaller in diameter than the trailing surface ofsaid land, and a relatively shallow axial surface flute formed on saidland from one end to the other, between said leading and trailingsurfaces, and

(b) a shank having a coolant passage terminating in a recess to receivea portion of one end of the bit opposite the cutting end, the walls ofsaid shank adjacent said recess having an axial projection to insertinto and overlie a portion of said shallow axial surface flute in saidland adjacent the surface of said bit to create a mechanical interlockfor a torque drive between said shank and said bit and to direct coolantto the relieved surface on said land and to the cutting end of said bit.

3. In a hole enlarging and finishing tool such as a reamer of the typehaving a shank with an axial coolant passage and a bit bonded to saidshank, that improvement which comprises:

(a) an elongate bit having a shank end and a cutting end and arelatively large flute with a cutting edge along one axial sidecontinuing in a radial edge extending inwardly from the periphery of thebit at the cutting end, and a land extending circumferentially from saidflute forming a bearing surface for said tool, said land having leadingand trailing axial surfaces extending along leading and trailing edgesthereof and being relieved slightly between said surfaces, the leadingsurface being slightly smaller in diameter than the trailing surface ofsaid land, and a relatively shallow axial surface flute formed on saidland from one end to the other, between said leading and trailingsurfaces, and

(b) a shank having a coolant passage terminating in a recess to receivea portion of one end of the bit opposite the cutting end, :the walls ofsaid shank adjacent said recess projecting axially over a portion ofsaid shallow axial surface flute to direct coolant to the relievedsurface of said land and to the cutting end of said bit.

No references cited.

WILLIAM W. DYER, JR., Primary Examiner.

1. IN A HOLE ENLARGING AND FINISHING TOOL SUCH AS A REAMER OF THE TYPEHAVING A SHANK WITH AN AXIAL COOLANT PASSAGE AND A BIT BONDED TO SAIDSHANK, THAT IMPROVEMENT WHICH COMPRISES: (A) AN ELONGATE BIT HAVING ASHANK END AND A CUTTING END AND A RELATIVELY LARGE FLUTE WITH A CUTTINGEDGE ALONG ONE AXIAL SIDE CONTINUING IN A RADIAL EDGE EXTENDING INWARDLYFROM THE PERIPHERY OF THE BIT AT THE CUTTING END, AND A LAND EXTENDINGCIRCUMFERENTIALLY FROM SAID FLUTE FORMING A BEARING SURFACE FOR SAIDTOOL, SAID LAND HAVING LEADING AND TRAILING AXIAL SURFACES EXTENDINGALONG LEADING AND TRAILING EDGES THEREOF AND BEING RELIEVED SLIGHTLYBETWEEN SAID SURFACES, THE LEADING SURFACE BEING SLIGHTLY SMALLER INDIAMETER THAN THE TRAILING SURFACE OF SAID LAND, AND A RELATIVELYSHALLOW AXIAL SURFACE FLUTE FORMED ON SAID LAND FROM ONE END TO THEOTHER, BETWEEN SAID LEADING AND TRAILING SURFACES, AND (B) A SHANKHAVING A COOLANT PASSAGE TERMINATING IN A RECESS TO RECEIVE A PORTION OFONE END OF THE BIT OPPOSITE THE CUTTING END, THE WALLS OF SAID SHANKADJACENT SAID RECESS HAVING AXIAL PROJECTIONS TO INSERT INTO SAIDOVERLIE SAID FLUTES ADJACENT THE SURFACE OF SAID BIT TO CREATE AMECHANICAL INTERLOCK FOR A TORQUE DRIVE BETWEEN SAID SHANK AND SAID BITAND TO DIRECT COOLANT DOWN SAID FLUTES TO THE CUTTING END OF SAID BIT.